1. Field of the Invention
The present invention relates to a clearance eliminating structure for a direct drive torque motor, and more particularly to a main shaft clearance eliminating structure for a direct drive torque motor, which can be used on the direct drive torque motor to simplify the assembly operation, improve the reliability of the motor, and it can eliminate the clearance of the main shaft to increase the service life of the product.
2. Description of the Prior Art
The motors are used more and more widely in modern industries, and are generally categorized into external rotor, internal rotor and so on. In addition to the high precision in the feeding transmission, the motor also has the advantages of low friction loss, high energy conversion efficiency and low noise, etc. Hence, the motor is obviously important to the modern industrial tool machines.
The existing direct drive motors are applied to the drive of the axis equipments, such as the automatic equipment, the indexing plate and each kind of tool machine. With reference to FIGS. 1 and 2, a clearance eliminating structure for the main shaft of a conventional direct drive torque motor utilizes the coil 101 of an outer stator 10 to closely cooperate with the magnet 111 of the inner rotor 11. A shaft 12 is fixed in the center of the inner rotor 11. The outer stator 10 includes an annular base 102, an annular aluminum sheet 103, a silicon steel sheet 104 and the coil 101 that are arranged sequentially from the outer to the inner periphery of the outer stator 10. A helical water passage 1031 is formed around the annular aluminum sheet 103, and a cooling water circulating hole 1021 is defined in the annular base 102. Thought it has been brought into use, this clearance eliminating structure for the main shaft of the conventional direct drive torque motor still has the following disadvantages:
First, this conventional direct drive torque motor must be mounted on a machine to carry out rotating operation and is not adapted for modular application since its heavy body is undetachable. Further, the market is awaiting new products which can be easily and independently used for various angle controlling, rotation speed controlling and precision controlling.
Second, if the conventional direct drive torque motor is mounted on a machine to carry out rotating operation, there are no appropriate assemblies that can be used to support and clamp the inner rotor 11 and the shaft 12 of the conventional direct drive torque motor, as a result, when the shaft 12 rotates, it will produce a clearance with respect to other components. This kind of shaft clearance will cause abrasion of the components, noise, and will considerably affect the life of the product.
Third, after the inner rotor 11 and the shaft 12 operated for a certain period of time, the clearance between them will become worse and worse due to the influence of deformation and abrasion. And the clearance of the shaft 12 will increase the abrasion and the noise of the respective components, and will considerably affect the life of the product.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.